Switch mechanism



Dec. 13, 1927.

W. M. GRANT SWITCH MECHANISM Filed March 2 4. 1921 2. Sheets-Sheet 1 QQI INVENTOR f ATTRNEY WITNEssEs;

Patented Dec. 13, 1927.

UNITED STATES PATENT OFFICE.

WILLIAM M. GRANT, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOLB, TWES'IINGHOUSE ELECTRIC &,MANUFACTURING COMPANY, A CORPORATION 0FPENNSYLVANIA.

SWITCH MECI-IANISM.

Application filed March 24, 1921.

My invention relates to switch mechanism and particularly to boxes forcontaining switch and fuse mechanism employed in electrical circuits.

An object of the invention is yto provide a box structure wherein thewalls of the box are provided with normally closed openings throughwhich meter leads may be inserted for the purpose of connecting the reedline at a point within the box, when it is desired to direct the currentthrough the meter for the purpose of making a motor test.

A further object or' the invention is to provide a box having the abovecharacteristics wherein the closures for the meterlead openings areretained in closed position so long as the box cover is in closedposition.

A further object is to provide a'box wherein the cover latch is switchcontrolled and cannot be opened so long as the switch is in closedposition and wherein the cover latch retains the closure for themetenlead openings in closed position so long as the latch is in closedposition.

A further object is to provide hinged closures for the meter-leadopenings that are yieldingly retained in closed position and which maybe swung inwardly to permit the insertion of the meter leads, after theswitch has been moved to open position.

A further object is to so interlock'the'box closures, including the boxcover, that they cannot be opened except in the proper sequence ofoperation, namely, the box cover iirst and the lead-opening closuressubsequently. j

A further object of the invention is to provide a meter-plug connectionhaving contact members similar to those of the fuses used in the box sothat, in order to connect the meter with the load, it is only necessaryto remove the fuse and to insert the plug connection in its place. Thedevice eliminates the necessity of cutting into the circuit kat a pointexternally oit' the box.

These and other objects, that will be apparent through the furtherdescription of the invention, are attained in the apparatus hereinafterdescribed and illustrated in the 50 accompanying drawings, wherein:

Figure'lis a front elevational view of a Serial N0. 455,053.

switch box embodying features of my in'- vention.

Fig. 2 is a longitudinal sectional view through a box showing theswitch-latch mechanism in side elevation.

b Fig. 3 is an end elevational view of a ox. e

Referring to the drawings, the apparatus includes a housing 4l havingkside and endwail members 5 andl 6, respectively, and a bottom wall 7.lVithin thehousing, an insulating base or panel 8 is secured to thebottom oi" the box, and two pairs or" fuse clips or jaws 9 and lO aremounted thereon. The clip l() is provided with a switch-contact memberll with which a rotatable switch 12 of the brush type engages.

The switch is pivoted at 13 upon the shaft carried by the box and servesto connect the terminal contact member 11 to the live terminal 14 thatis mounted adjacent the housing cover l5. The switch is actuated bymeans or' an operating handle 16 that is pivotally attached to the coverand is connected to the switch by means of ltoggle links 17 and 18.

As shown in F ig. 2, the switch is in open position. W hen the handle ismoved ton ward the left, the toggle links are moved to set position andthe switch blades are moved to closed position, as indicated in brokenlines in Fig. 2. The spring 19 serves to normally retain the switch inopen position, and the toggle links, when in set position, hold theswitch in engagement with the contact members. The 4switch may be movedto open position by moving the knee pivot 21 of the toggle toward thelett past dead center, therebyv causing the collapse of the toggle.

The housing 5 is provided with an opening 22 through which the fuse jawmembers 9 and l0 and the cartridge-fuse element 26y mounted thereon areaccessible and the ppening is closed by a door 24 that is hinged to thecover l5, as at 20. The free end oit the cover is provided with arotatable latch 26 having an exteriorly disposed operating handle 27. Aslide member 28 is slidably attached to the inside of the 4door and ispivoted at 29 to the latch 26and extends toward the switch and abuts thefree end of a plunger member 31 that is attached to the toggle kneepivot 21, which is supported at its tree end upon a pin 32 that issecured to the cover 15 and which projects through the slot 33 in theplunger member.

It will be apparent from the foregoing that, when the switch handle ismoved to the left, the'plunger 31 will be mo ved to the right, and, byreason of its engagement with the slide member 28, will cause the latchto be so rotated that it is moved beneath the ledge 34 provided at theupper end olf the edge 6. The closing movement of the switch, therefore,causes the door 24 to be locked in closed position. On the other hand,the latch cannot be turned to. open position without first causing thecollapse oit the toggle. It is apparent, therefore, that the door cannotbe opened while the switch is in closed position.

rIhe apparatus above described is disclosed in Patent No. 1,324,555,issued December 9, 1919 to'H. F. Krantz, and no claim is made to any ofthe features above described except in combination with certain4features of my invention to be hereinafter disclosed.

The object oit my invention is to provide suitable openings in the boxot the type described and in boxes having similar characteristics forthe purpose oill inserting meter leads when it is desired to connect ameter with the ieed line for the purpose ol testing motors and otherapparatus.

It has been the usual practice to cut the wires exteriorly ot' the boxfor the purpose of connecting the meter in series with the apparatusbeing tested. By providing suitable openings in the housing that arenormally held in closed position and by providing a simple meter-leadplug that may be attached to standard fuse jaw members or receptaclesand which may be readily inserted through the openings, the testingoperation is greatly simplified and considerable time is saved.

In carrying out my invention, I provide the end ot' the housing adjacentto the iiuse jaws with oblong openings 35 and 36 that are closed bydoors 37 .and 38, respectively. The doors are hinged between the ledge34 at the top of the end wall and the projections 39 which are securedto the end wall, by means of the hinged pins 41 about which springs 42are wound. The center portion 43 of the springs bears against the entireside of the door while the free ends ot the spring engage the end wall,The springs normally exert tension tending to yieldingly hold the doorsin closed position.

Each door is provided, at its free end, with a tongue 44 which occupiesa position between the latch 26 and the end wall 6. So long as the latchis in closed position and so long as the door 24 remains in closedposition, the closures 37 and 38 cannot be opened because ol theengagement of the latch with the tongues 44. The door 35 1s providedwith a notch 40, so located as to clear the depending flange of thelatch 26 when the latch is in open position.

The meter-terminal plug comprises an insulating body 45, upon the endsof which separate contact members 4G and 47 are se cured by means olscrews 48. Terminal sockets 49 and 51 are attached to the contactmembers, respectively, and the flexible conductors 52 and53 are securedthereto. The contact members are similar to those of the fuses used inthe box and, therefore, tit within the fuse clips and establish acircuit through the meter when the plug is inserted within the clips inlieu of the fuse.

The operation is as follows: The switch handle is first moved to openposition, thereby cutting off lthe current through the fuse clips andpermitting open movement of the latch. However, if the switch is notfirst thrown open, opening movement of the latch 26 will cause it to bemoved to open position before the cover is released. Vhen the cover isopened, the latch 26 is withdrawn thereby from the path oi the doors 37and 38. These doors may be opened and the meter-terminal plug insertedthrough either of the openings 35. Gne of the -fuses is removed from theclip and a plug inserted in lieu thereof. The door 24 may then be closedand the switch subsequently closed to supply current Yl'or the test. Theapparatus being tested will, of course, be protect-ed bythe remainingfuse.

The construction is simple, and the meterlead doors may be applied to avariet of boxes and switch structures other than t lose here shown.

While I have illustrated and described but one embodiment oi minvention, it will be apparent to those skilled in the art that variousmodiiications, changes, substitutions, additions and omissions may bemade in the apparatus described without departing from the spirit' andscope of the invention, as set Yforth in the appended claims.

I claim as my invention 1. The combination with a housing for electricalfixtures having a movable cover, a. latch for the cover and an openingfor the temporary insertion oit conductor elements, of a movable doei'for closing the opening and means for retaining the movable door closedso long as the cover is in latched position.

2. The combination with a housing for electrical fixtures having amovable cover, a latch for the cover and an opening for the temporaryinsertion of conductor elements, of a movable door member closing theopen-l ing and normally yieldinfly retained in closed position and meansIor holding the door closed so long as the cover is in latched position.

3. The combinationpwith a housing for a switch having a movable coverand an Opening for the temporary insertion of conductor elements, and alatch for retaining the cover in closed position so long as the switchis in closed position7 of a movable door for closing the opening andadapted to be retained in closed position by the said latch so long asthe latch is in closed position.

4. A b'ox for electrical fixtures comprising a housing closed by amovable cover, a latch for the cover, the said box being provided Withan opening, and a door for the opening mounted interior-ly of the boxand retained in closed position by the cover s0 long as the latter is inlatched position.

In testimony whereof, I have hereunto subscribed my name this 17th dayof March 20 WILLIAM M. GRANT.

